Dr. Martin Tobin, a pulmonary specialist, testified that Floyd died from a 'low lever of oxygen' caused by 'shallow breathing'.
Dr. Tobin outlined multiple factors that cut off Floyd's oxygen - including the handcuffs, his prone position on the street, and Chauvin's knees - one on Floyd's neck and the other on his back.
Tobin also said Floyd's preexisting health conditions were not a factor in his death.